The goals of this project are to define the nature and interactions of the various components which function in the regulation of sulfur metabolism in S. typhimurium. Most of our efforts deal with the regulation of cysteine biosynthesis, although more recently we have begun to study the regulation of L-cystine transport in this organism. BIBLIOGRAPHIC REFERENCES: Kedrich, N.M., Foote, L.J., and Hulanicka, M.D., "Studies on the Mechanism of Inhibition of Salmonella typhimurium by 1,2,4-Triazole," J. Biol. Chem. 250, 7324-7331 (1975). Baptist, E.W. and Kredich, N.M., "Regulation of L-Cystine transport in Salmonella typhimurium" Fed. Proc. 35, 1665 (1976). Abstract.